WO2008037431A1 - Répresseurs transcriptionnels de la signalisation par cytokinine et leur utilisation - Google Patents

Répresseurs transcriptionnels de la signalisation par cytokinine et leur utilisation Download PDF

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WO2008037431A1
WO2008037431A1 PCT/EP2007/008331 EP2007008331W WO2008037431A1 WO 2008037431 A1 WO2008037431 A1 WO 2008037431A1 EP 2007008331 W EP2007008331 W EP 2007008331W WO 2008037431 A1 WO2008037431 A1 WO 2008037431A1
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seq
plant
dna
root
fusion protein
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PCT/EP2007/008331
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Thomas SCHMÜLLING
Alexander Heyl
Eswar Ramireddy
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Freie Universität Berlin
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Priority to PL07818415T priority Critical patent/PL2121935T3/pl
Priority to EP07818415A priority patent/EP2121935B1/fr
Priority to US12/442,662 priority patent/US9187761B2/en
Priority to AU2007302306A priority patent/AU2007302306A1/en
Priority to CA2667396A priority patent/CA2667396C/fr
Priority to AT07818415T priority patent/ATE516358T1/de
Publication of WO2008037431A1 publication Critical patent/WO2008037431A1/fr

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    • C12N15/00—Mutation or genetic engineering; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification; Use of hosts therefor
    • C12N15/09—Recombinant DNA-technology
    • C12N15/63—Introduction of foreign genetic material using vectors; Vectors; Use of hosts therefor; Regulation of expression
    • C12N15/79—Vectors or expression systems specially adapted for eukaryotic hosts
    • C12N15/82—Vectors or expression systems specially adapted for eukaryotic hosts for plant cells, e.g. plant artificial chromosomes (PACs)
    • C12N15/8241—Phenotypically and genetically modified plants via recombinant DNA technology
    • C12N15/8261—Phenotypically and genetically modified plants via recombinant DNA technology with agronomic (input) traits, e.g. crop yield
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K14/00—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
    • C07K14/415—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from plants
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    • C12N15/00—Mutation or genetic engineering; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification; Use of hosts therefor
    • C12N15/09—Recombinant DNA-technology
    • C12N15/11—DNA or RNA fragments; Modified forms thereof; Non-coding nucleic acids having a biological activity
    • C12N15/62—DNA sequences coding for fusion proteins
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    • C12N15/00—Mutation or genetic engineering; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification; Use of hosts therefor
    • C12N15/09—Recombinant DNA-technology
    • C12N15/63—Introduction of foreign genetic material using vectors; Vectors; Use of hosts therefor; Regulation of expression
    • C12N15/79—Vectors or expression systems specially adapted for eukaryotic hosts
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
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    • C12N15/00—Mutation or genetic engineering; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification; Use of hosts therefor
    • C12N15/09—Recombinant DNA-technology
    • C12N15/63—Introduction of foreign genetic material using vectors; Vectors; Use of hosts therefor; Regulation of expression
    • C12N15/79—Vectors or expression systems specially adapted for eukaryotic hosts
    • C12N15/82—Vectors or expression systems specially adapted for eukaryotic hosts for plant cells, e.g. plant artificial chromosomes (PACs)
    • C12N15/8201—Methods for introducing genetic material into plant cells, e.g. DNA, RNA, stable or transient incorporation, tissue culture methods adapted for transformation
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
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    • C12N15/00—Mutation or genetic engineering; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification; Use of hosts therefor
    • C12N15/09—Recombinant DNA-technology
    • C12N15/63—Introduction of foreign genetic material using vectors; Vectors; Use of hosts therefor; Regulation of expression
    • C12N15/79—Vectors or expression systems specially adapted for eukaryotic hosts
    • C12N15/82—Vectors or expression systems specially adapted for eukaryotic hosts for plant cells, e.g. plant artificial chromosomes (PACs)
    • C12N15/8241—Phenotypically and genetically modified plants via recombinant DNA technology
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
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    • C12N15/00—Mutation or genetic engineering; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification; Use of hosts therefor
    • C12N15/09—Recombinant DNA-technology
    • C12N15/63—Introduction of foreign genetic material using vectors; Vectors; Use of hosts therefor; Regulation of expression
    • C12N15/79—Vectors or expression systems specially adapted for eukaryotic hosts
    • C12N15/82—Vectors or expression systems specially adapted for eukaryotic hosts for plant cells, e.g. plant artificial chromosomes (PACs)
    • C12N15/8241—Phenotypically and genetically modified plants via recombinant DNA technology
    • C12N15/8261—Phenotypically and genetically modified plants via recombinant DNA technology with agronomic (input) traits, e.g. crop yield
    • C12N15/8291—Hormone-influenced development
    • C12N15/8295—Cytokinins
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2319/00—Fusion polypeptide
    • C07K2319/80—Fusion polypeptide containing a DNA binding domain, e.g. Lacl or Tet-repressor
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A40/00—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production
    • Y02A40/10—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production in agriculture
    • Y02A40/146—Genetically Modified [GMO] plants, e.g. transgenic plants

Definitions

  • the invention relates to fusion proteins capable of acting as transcriptional repressors of cytokinin signaling, to polynucleotides encoding these fusion proteins, to vectors and cells comprising these polynucleotides, and to transgenic plants and parts thereof comprising these polynucleotides, vectors, and cells.
  • the invention further relates to a process for making these transgenic plants and to the use of these transgenic plants for producing seeds of enhanced size, with enhanced seed filling, with reduced seed loss and/or with more rapid germination, and/or for producing a live root system with increased root mass, root length and/or root branching.
  • the invention also relates to a method for enhancing the seed size, for enhancing seed filling, for reducing seed loss, and/or for reducing germination time and/or reproduction time, and/or for enhancing the root mass, root length and/or root branching of a plant and to seeds obtainable by the methods of the present invention.
  • the plant hormone cytokinin is involved in many developmental processes and plays a critical role in numerous physiological responses to changes in the environment (Mok and Mok, 2001). In recent years significant progress has been made towards the understanding of how the cytokinin signal is perceived and transduced (Ferreira and Kieber, 2005; Grefen and Harter, 2004; Heyl et al., 2006; Hwang et al., 2002; Hwang and Sakakibara, 2006; Kakimoto, 2003; Mizuno, 2004). In the current model, which has been mainly developed in Arabidopsis, the hormone is perceived by membrane-bound hybrid histidine kinase receptors (AHKs), which auto-phosphorylate upon binding of the hormone ligand.
  • AHKs membrane-bound hybrid histidine kinase receptors
  • AHPs histidine phospho-transfer protein
  • ARRs B-type response regulators
  • B-type response regulators are characterized by the presence of Myb-class DNA binding domain, called GARP domain, in addition to the response regulator domain.
  • GARP domain Myb-class DNA binding domain
  • CRES-T The chimeric repressor silencing technology
  • the length and the repression potential of the EAR motif were improved resulting in the so-called SRDX motif (Hiratsu et al., 2003). Fusion of this motif to transcriptional activators converts them into dominant repressors (Hiratsu et al., 2003). Interestingly, these dominant repressors may repress not only the transcription of their own target genes, but also the expression of target genes of other members of their respective gene family. For example, the CUCl and CUC2 transcription factors are functionally redundant and a loss of function phenotype is seen only in the cucl cuc2 double mutant plants, while mutation of both single genes does not
  • the technical problem underlying the instant invention is to provide a method for making seeds of enhanced size, with more rapid germination, with enhanced yield, with
  • the present invention relates to a fusion protein comprising, essentially consisting or consisting of
  • the present invention relates to a fusion protein comprising, essentially consisting or consisting:
  • the present invention relates to a polynucleotide comprising a nucleic acid sequence encoding said fusion protein, a vector comprising said polynucleotide, a cell comprising said polynucleotide or said vector, and a transgenic plant comprising said polynucleotide, said vector, or said cell.
  • the invention is further directed to parts, cells, or seeds of said transgenic plant, and to plants or propagating material thereof regenerated from said transgenic plant, parts, cells or seeds.
  • the present invention is directed to a process for making the above transgenic plant, parts, cells, seeds or propagating material, wherein the above vector is 5 introduced in a gene technological manner into cells of a plant, wherein the cells are transformed.
  • the present invention relates to the use of the above transgenic plant, parts, cells, seeds or propagating material for producing seeds of enhanced size, with enhanced seed filling, with reduced seed loss and/or with more rapid germination, wherein the i 0 transgenic plants are cultured under culturing conditions and the preferably mature seeds are harvested.
  • the present invention relates to the use of the above transgenic plant, parts, cells, seeds or propagating material for producing a live root system with increased root mass, root length and/or root branching, wherein the transgenic plant is cultured under [ 5 culturing conditions.
  • the present invention is directed to the use of a transgenically expressed fusion protein as defined above for enhancing the seed size, the seed filling, the root mass, root length and/or the root branching and/or for reducing seed loss and/or germination time of a plant.
  • the present invention is directed to the use of a transgenically expressed fusion protein as defined above for modifying the characteristics of wood, for altering shoot architecture, for altering leaf senescence and other senescence processes and/or for altering the timing of reproduction.
  • the invention relates to a method for enhancing the seed size, seed 15 filling, the root mass, the root length and/or the root branching and/or for reducing seed loss and/or germination time of a plant, comprising the steps of introducing by genetic engineering into the plant a nucleic acid; and expressing said nucleic acid, wherein the nucleic acid is the polynucleotide or the vector as defined above.
  • the present invention relates to a method for making seeds of enhanced size, with enhanced seed filling, with reduced seed loss and/or with more rapid germination, wherein the transgenic plant, parts thereof, or seeds as described above are cultured under culturing conditions and preferably mature seeds being produced thereby are harvested.
  • the present invention is directed to seeds obtainable by any of the above methods.
  • the present invention relates to a method for making plants with increased root mass, root length and/or root branching and/or for reducing seed loss and or germination time of a plant, wherein the transgenic plant, parts, cells, seeds or propagating material as defined above are cultured under culturing conditions.
  • the terms used herein are defined as described in "A multilingual glossary of biotechnological terms: (IUPAC Recommendations)", Leuenberger, H.G.W, Nagel, B. and K ⁇ lbl, H. eds. (1995), Helvetica Chimica Acta, CH-4010 Basel, Switzerland).
  • a “DNA binding factor” is to be understood as a polypeptide which is capable of binding in a sequence specific manner to DNA by virtue of a DNA binding domain.
  • DNA binding factors are capable of making various contacts with the nucleotides in the major or minor groove of the DNA.
  • DNA binding factors recognize sequence elements (DNA motifs) of 4 to 20 nucleotides in length.
  • DNA binding factors only specifically recognize their respective DNA motif, if they homo- or heterodimerize.
  • a "DNA binding factor” within the meaning of the present invention will preferably comprise both a DNA binding domain and a dimerization domain. Examples of such dimerization domains include without limitation so called leucine zippers or helix-loop-helix motifs (HLH).
  • the DNA binding factor preferably is devoid of any additional domain, e.g. activation domains, which are not required for sequence specific DNA binding.
  • the term "DNA binding factor” encompasses isolated DNA-binding domains of DNA-binding proteins and also full length DNA binding proteins comprising further domains, such as the response regulator domain, as well as fragments and derivatives of such DNA binding proteins, provided that these fragments or derivatives are capable of sequence specific binding to DNA.
  • polypeptide e.g. a DNA binding factor
  • a target sequence within a nucleic acid, e.g. to a B-type ARR DNA motif, but not to other nucleotide sequences.
  • Whether a polypeptide binds specifically or not to a target sequence can be determined by methods well-known to the person skilled in the art, such as band-shift assays, DNA protection assays, DNA footprinting etc.
  • a "DNA binding domain” is that region of a DNA-binding factor which directly interacts with the DNA and, thereby, mediates sequence specific binding to the DNA.
  • the amino acid sequences of preferred DNA-binding domains of the invention are shown in Fig. l(a).
  • a "B-type Arabidopsis response regulator (ARR) DNA motif is that region on a DNA sequence to which the DNA binding factor or the DNA binding domain of the present invention is capable to bind.
  • the DNA motif found optimal for binding of B-type ARRs is 5'- (A/G)GAT(T/C)-3' with the GAT motif in the middle being of special importance (Sakai H. et al. Arabidopsis ARRl and ARR2 response regulators operate as transcriptional activators. Plant J 2000, 24:703-711; Hosoda K. et al.: Molecular structure of the GARP family of plant Myb-related DNA binding motifs of the Arabidopsis response regulators. Plant Cell 2002, 14:2015-2029).
  • 5 ⁇ -AGATT-3' was found to be optimal for ARRl, ARR2 and ARRlO (Sakai et al. 2000; Hosoda et al. 2002), whereas 5'-GGATT-3' was found for ARRI l (Imamura A. et al.: In vivo and in vitro characterization of the ARR 11 response regulator implicated in the His-Asp phosphorelay signal transduction in Arabidopsis thaliana. Plant Cell Phys 2003, 44:122-131). It is further considered within the present invention that additional DNA sequences close by could be involved in regulation and mediate specificity.
  • a B-type Arabidopsis response regulator comprises 1, 2, 3, 4, 5, or 6 additional nucleotides 5' and/or 3' of the core motif 5'-(A/G)GAT(T/C)-3' which can be derived from the promoter of an ARR regulated gene, i.e. from the sequences naturally flanking the core element 5' and/or 3'.
  • Preferred examples of such promoters and elements are described in Sakai H. et al. (2000) supra and Hosoda K. et al. (2002) supra. The person skilled in the art is well aware of techniques allowing to isolate other proteins binding specifically to the "B-type ARR DNA motif.
  • B-type ARRs binding to DNA sequences other than 5'-(A/G)GAT(T/C)-3' or DNA binding domains thereof can be used as a DNA binding factor according to the present invention provided that these B-type ARRs take part in cytokinin signaling and/or are homologous to the B-type response regulators set forth herein, especially to the B-type response regulators having the amino acid sequences as set forth in SEQ ID NOs: 12 to 50.
  • transcriptional repressor domain is to be understood as a polypeptide which is capable of achieving transcriptional repression when fused to a DNA binding factor or DNA binding domain.
  • Transcriptional repression can be measured as the reduction of the expression of a reporter gene, e.g. luciferase, in a reporter gene assay.
  • a "transcriptional repressor domain" within the meaning of the present invention is capable of reducing the expression of such a reporter gene by at least 10%, preferably by at least 20%, preferably by at least 30%, preferably by at least 40%, preferably by at least 50%, preferably by at least 60%, preferably by at least 70%, preferably by at least 80%, preferably by at least 90%, more preferably by at least 95%, even more preferably by at least 98% or most preferably by at least 99%.
  • Homologs are defined herein as two nucleic acids or polypeptides that have similar, or “homologous", nucleotide or amino acid sequences, respectively. Homologs within the meaning of the present application are to be understood as naturally occurring nucleic acids or polypeptides. Homologs include allelic variants, orthologs, and paralogs. In a narrow sense, two nucleic acids or polypeptides are considered homologs, if they share a common evolutionary ancestry. Within the context of the present application two nucleic acids or polypeptides are also considered “homologs” if they share a certain degree of sequence identity regardless whether said two nucleic acids or polypeptides share a common ancestry or not.
  • two nucleic acids or polypeptides shall be considered as homologs, if they exhibit at least 30% sequence identity, preferably at least 40% sequence identity, preferably at least 50% sequence identity, more preferably at least 60% sequence identity, more preferably at least 70% sequence identity, more preferably at least 80% sequence identity, even more preferably at least 90% sequence identity, and most preferably at least 95% sequence identity.
  • the homologs of the present invention exhibit the indicated homology, i.e. identity, and preferably the homology is over a continous stretch of 20, 30, 40, 45, 50, 60, 70, 80, 90, 100 or more amino acids or the respective encoding nucleic acids, i.e.
  • the continous stretch of homologous amino acids spans the DNA binding domain or the DNA binding domain and the dimerization domain.
  • the similarity of nucleotide and amino acid sequences i.e. the percentage of sequence identity, can be determined via sequence alignments. Such alignments can be carried out with several art-known algorithms, preferably with hmmalign (HMMER package, http://hmmer.wustl.edu/) or with the CLUSTAL algorithm (Thompson, J. D., Higgins, D. G. & Gibson, T. J. (1994) Nucleic Acids Res. 22, 4673-80) available e.g.
  • sequence identity may be calculated using e.g. BLAST, BLAT or BlastZ (or BlastX).
  • sequence matching analysis may be supplemented by established homology mapping techniques like Shuffle-LAGAN (Brudno M., Bioinformatics 2003b, 19 Suppl 1 :154-I62) or Markov random fields. When percentages of sequence identity are calculated, these percentages are typically calculated in relation to the full length of the longer sequence.
  • variant is to be understood herein as a polypeptide which differs in comparison to the protein or protein domain from which it is derived by one or more changes in the amino acid sequence.
  • variant and the term “derivative” are used interchangeably throughout this application.
  • a variant is constructed artificially, preferably by gene-technological means.
  • the protein or protein domain from which the variant is derived is a wild-type protein or protein domain.
  • the variants of the present invention may also be derived from homologs or from artificially constructed variants, provided that the variants of the DNA binding factor of the present invention are capable of specifically binding to a B-type ARR DNA motif, and provided that the variants of the repressor domain of the present invention are capable of achieving transcriptional repression when fused to a DNA binding factor.
  • the changes in the amino acid sequence may be amino acid exchanges, insertions, deletions, N-terminal truncations, or C-terminal truncations, or any combination of these changes, which may occur at one or several sites.
  • the amino acid exchanges may be conservative or non-conservative.
  • a DNA binding factor or a DNA binding domain of the present invention differs from the protein or domain from which it is derived at least by 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100 or more amino acid exchanges, preferably conservative amino acid changes.
  • a repressor domain of the present invention differs from the protein or domain from which it is derived at least by 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100 or more amino acid exchanges, preferably conservative amino acid changes.
  • Variants may additionally or alternatively comprise deletions of amino acids, which may be N-terminal truncations, C-terminal truncations or internal deletions or any combination of these.
  • Such a deletion variant may be naturally occurring or it may be constructed artificially, preferably by gene-technological means.
  • the protein or protein domain from which the deletion variant is derived is a wild-type protein.
  • the variants of the present invention carrying deletions may also be derived from homologs or from artificially constructed variants, provided that the deletion variants of the DNA binding factor of the present invention are capable of specifically binding to a B-type ARR DNA motif, and provided that the deletion variants of the repressor domain of the present invention are capable of achieving transcriptional repression when fused to a DNA binding factor.
  • a fragment of the DNA binding factor of the present invention is derived from a B-Type ARR having the amino acid sequence as shown in any one of SEQ ID NOs: 12 to 22.
  • a deletion variant of the DNA binding factor of the present invention comprises the DNA binding domain of a B-Type ARR having the amino acid sequence as shown in any one of SEQ ID NOs: 1 to 11.
  • a fragment has a deletion of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100 or more amino acids at its N-terminus and/or C-terminus.
  • a variant of the DNA binding factor of the present invention is derived from a B-Type ARR having the amino acid sequence as shown in any one of SEQ ID NOs: 12 to 22.
  • a variant of the DNA binding factor of the present invention is derived from the DNA binding domain of a B-Type ARR having the amino acid sequence as shown in any one of SEQ ID NOs: 1 to 11.
  • "Non-conservative substitutions” or “non-conservative amino acid exchanges” are defined as exchanges of an amino acid by another amino acid listed in a different group of the six standard amino acid groups shown below:
  • hydrophobic Met, Ala, VaI, Leu, He
  • neutral hydrophilic Cys, Ser, Thr
  • EAR motif is a repression motif of transcriptional repressors of the class II ethylene response factors (ERF).
  • the EAR motif or variations of it are found in numerous plant transcriptional repressors (Kazan, 2006; Ohta et al., 2001; Tiwari et al., 2004).
  • the minimal consensus sequence of the EAR motif is the amino acid sequence DLELRL (SEQ ID NO: 51; Hiratsu K. et al. (2004) Identification of the minimal repression domain of SUPERMAN shows that the DLELRL hexapeptide is both necessary and sufficient for repression of transcription in Arabidopsis. BBRC 321. 172-178).
  • An especially preferred embodiment of the EAR motif having improved repression potential is the so-called SRDX motif (SEQ ID NO: 52; (Hiratsu et al., 2003)).
  • nuclear localization signal (NLS) usable in the present invention is not particularly limited, provided that the signal is capable of achieving transport of the polypeptide to which it is bound to the nucleus of a cell.
  • Nuclear localization signals comprise inter alia: PKKKRKV (SEQ ID NO: 53), KIPIK (SEQ ID NO: 54), SPPKAVKRPAATKKAGQAKKKKLDKEDES (SEQ ID NO: 55),
  • MEEAVTMAPAAVSSAVVGDPMEYNAILRRKLEEDLE SEQ ID NO: 56
  • KKRARL VRNRESAQLS RQRKK SEQ ID NO: 57
  • a non-limiting list of such nuclear localization signals can be found for example in: Raikhel, N. (1992) Nuclear targeting in plants. Plant Phys. 100. 1627-1632; which is incorporated herein by reference in its entirety. Nuclear localization signals which are especially well-suited in the fusion proteins of the present invention can be found in Fig. 2 on p. 1628 of Raikhel, N. (1992), supra.
  • promoter includes the transcriptional regulatory sequences derived from a classical eukaryotic genomic gene, typically including the TATA box which is required for accurate transcription initiation, with or without a CCAAT box sequence and additional regulatory or control elements (e.g. upstream activating sequences, repressors, enhancers and silencers) which alter gene expression in response to developmental and/or external stimuli, or in a tissue-specific manner.
  • TATA box which is required for accurate transcription initiation
  • CCAAT box sequence e.g. upstream activating sequences, repressors, enhancers and silencers
  • promoter also includes the transcriptional regulatory sequences of a classical prokaryotic gene, in which case it may include a -35 box sequence and/or a -10 box transcriptional regulatory sequences.
  • promoter is also used to describe a synthetic or fusion molecule, or derivative which confers, activates or enhances expression of a nucleic acid molecule in a cell, tissue or organ. Promoters may contain additional copies of one or
  • regulatory elements to further enhance expression and/or to alter the spatial expression and/or temporal expression of a nucleic acid molecule to which it is operatively linked.
  • Such regulatory elements may be placed adjacent to a heterologous promoter sequence to drive expression of a nucleic acid molecule in response to e.g. copper, glucocorticoids, dexamethasone, tetracycline, gibberellin, cAMP, abscisic acid, auxin, wounding, ethylene,
  • the promoter preferably is a plant-expressible promoter sequence. Promoters that also function or solely function in non-plant cells such as bacteria, yeast cells, insect cells and animal cells are not excluded from the invention.
  • D expressible is meant that the promoter sequence, including any additional regulatory elements added thereto or contained therein, is at least capable of inducing, conferring, activating or enhancing expression in a plant cell, tissue or organ, preferably a monocotyledonous or dicotyledonous plant cell, tissue, or organ.
  • plant-operative and “operative in a plant” when used herein, in respect of a promoter sequence, shall be taken
  • Regulatable promoters as part of a binary viral plant expression system are also known to the skilled artisan (Yadav 1999 - WO 99/22003; Yadav 2000 - WO 00/17365).
  • a "regulatable promoter sequence” is a promoter that is capable of conferring expression of a structural gene in a particular cell, tissue, or organ or group of
  • a regulatable promoter sequence may be a promoter sequence that confers expression of a gene to which it is operatively linked in a particular location within the plant or alternatively, throughout the plant under a specific set of conditions, such as following induction of gene expression by a chemical compound or other elicitor.
  • the regulatable promoter used in the performance of the present invention confers expression in a specific location within the plant, either constitutively or following induction, however, not in the whole plant under any circumstances.
  • tissue-specific promoter sequences include cell-specific promoter sequences, tissue-specific promoter sequences, organ-specific promoter sequences, cell cycle specific gene promoter sequences, inducible promoter sequences and constitutive promoter sequences that have been modified to confer expression in a particular part of the plant at any one time, such as by integration of said constitutive promoter within a transposable genetic element (Ac, Ds, Spm, En, or other transposon).
  • tissue-specific shall be taken to indicate that expression is predominantly in a particular tissue or tissue-type, preferably of plant origin, albeit not necessarily exclusively in said tissue or tissue-type.
  • organ-specific shall be taken to indicate that expression is predominantly in a particular organ, preferably of plant origin, albeit not necessarily exclusively in said organ.
  • cell cycle specific shall be taken to indicate that expression is predominantly cyclic and occurring in one or more, not necessarily consecutive phases of the cell cycle albeit not necessarily exclusively in cycling cells, preferably of plant origin.
  • an "inducible promoter” is a promoter the transcriptional activity of which is increased or induced in response to a developmental, chemical, environmental, or physical stimulus.
  • a "constitutive promoter” is a promoter that is transcriptionally active throughout most, but not necessarily all parts of an organism, preferably a plant, during most, but not necessarily all phases of its growth and development.
  • Those skilled in the art will readily be capable of selecting appropriate promoter sequences for use in regulating appropriate expression of the fusion protein from publicly-available sources, without undue experimentation. Placing a nucleic acid molecule under the regulatory control of a promoter sequence, or in operative connection or linkage with a promoter sequence, means positioning said nucleic said molecule such that expression is controlled by the promoter sequence.
  • a promoter is usually, but not necessarily, positioned upstream, or at the 5'-end, and within 2 kb of the start site of transcription, of the nucleic acid molecule which it regulates, albeit enhancers and silencers, which are also comprised by the term "promoter" may be placed further away from the transcriptional start site. It is thought that these elements bind to proteins capable of long range action due to looping out of the intervening sequence. In the construction of heterologous promoter/structural gene combinations it is generally preferred to position the promoter at a distance from the gene transcription start site that is approximately the same as the distance between that promoter and the gene it controls in its natural setting (i.e., the gene from which the promoter is derived).
  • promoters suitable for use in gene constructs of the present invention include those listed in Table 1, amongst others. Table 1 consists of three parts marked with Roman numbers I, III and IV.
  • Table 1 Promoters usable in the invention.
  • the promoters listed in Table 1 are provided for the purposes of exemplification only and the present invention is not to be limited by the list provided therein. Those skilled in the art will readily be in a position to provide additional promoters that are useful in performing the present invention. In the case of constitutive promoters or promoters that induce expression throughout the entire plant, it is preferred that such sequences are modified by the addition of nucleotide sequences derived from one or more of the tissue-specific promoters listed in Table 1, or alternatively, nucleotide sequences derived from one or more of the above-mentioned tissue-specific inducible promoters, to confer tissue-specificity thereon.
  • the CaMV 35S promoter may be modified by the addition of maize Adhl promoter sequence, to confer anaerobically-regulated root-specific expression thereon, as described previously (Ellis et al., 1987).
  • Another example describes conferring root specific or root abundant gene expression by fusing the CaMV35S promoter to elements of the maize glycine-rich protein GRP3 gene (Feix and Wulff 2000 - WO 00/15662). Such modifications can be achieved by routine experimentation by those skilled in the art.
  • the term "terminator" refers to a DNA sequence at the end of a transcriptional unit which signals termination of transcription.
  • Terminators are 3 '-non-translated DNA sequences containing a polyadenylation signal, which facilitates the addition of polyadenylate sequences to the 3 '-end of a primary transcript. Terminators active in cells derived from viruses, yeasts, moulds, bacteria, insects, birds, mammals and plants are known and described in the literature. They may be isolated from bacteria, fungi, viruses, animals and/or plants.
  • terminators particularly suitable for use in the gene constructs of the present invention include the Agrobacterium tumefaciens nopaline synthase (NOS) gene terminator, the Agrobacterium tumefaciens octopine synthase (OCS) gene terminator sequence, the Cauliflower mosaic virus (CaMV) 35S gene terminator sequence, the Oryza sativa ADP- glucose pyrophosphorylase terminator sequence (t3'Bt2), the Zea mays zein gene terminator sequence, the rbcs-1 A gene terminator, and the rbcs-3A gene terminator sequences, amongst others.
  • NOS nopaline synthase
  • OCS Agrobacterium tumefaciens octopine synthase
  • CaMV Cauliflower mosaic virus
  • t3'Bt2 Oryza sativa ADP- glucose pyrophosphorylase terminator sequence
  • Zea mays zein gene terminat
  • Preferred promoter sequences of the invention include root specific promoters such as but not limited to the ones listed in Table 1 and as outlined in the Examples. Those skilled in the art will be aware of additional promoter sequences and terminator sequences which may be suitable for use in performing the invention. Such sequences may readily be used without any undue experimentation.
  • organogenesis means a process by which shoots and roots are developed sequentially from meristematic centres.
  • embryogenesis means a process by which shoots and roots develop together in a concerted fashion (not sequentially), whether from somatic cells or gametes.
  • Agrobacterium is meant a member of the Agrobacteriaceae, more preferably Agrobacterium or Rhizobacterium and most preferably Agrobacterium tumefaciens.
  • T-DNA or transferred DNA
  • T-DNA borders or transferred DNA
  • T-DNA borders or transferred DNA
  • RB right T-DNA border
  • LB left T-DNA border
  • Such a border comprises a core sequence flanked by a border inner region as part of the T-DNA
  • Border core sequences are indispensable for recognition and processing by the Agrobacterium nicking complex consisting of at least VirDl and VirD2.
  • T-DNA transformation vector or "T-DNA vector” is meant any vector encompassing a T-DNA sequence flanked by a right and left T-DNA border consisting of at least the right and left border core sequences, respectively, and used for transformation of any eukaryotic cell.
  • T-DNA vector backbone sequence or "T-DNA vector backbone
  • !0 sequences is meant all DNA of a T-DNA containing vector that lies outside of the T-DNA borders and, more specifically, outside the nicking sites of the border core imperfect repeats.
  • the current invention includes optimized T-DNA vectors such that vector backbone integration in the genome of a eukaryotic cell is minimized or absent.
  • optimized T- DNA vector is meant a T-DNA vector designed either to decrease or abolish transfer of
  • T-DNA vectors 15 vector backbone sequences to the genome of a eukaryotic cell.
  • T-DNA vectors are known to the one familiar with the art and include those described by Hanson et al. (1999) and in WO 99/01563.
  • the current invention clearly considers the inclusion of a DNA sequence encoding a fusion protein in any T-DNA vector comprising binary transformation vectors, super-binary transformation vectors, co-integrate transformation vectors, bi-derived
  • binary transformation vector is meant a T-DNA transformation vector comprising: (a) a T-DNA region comprising at least one gene of interest and/or at least one selectable marker active in the eukaryotic cell to be transformed; and (b) a vector backbone region comprising at least origins of replication active in E. coli and Agrobacterium and markers for selection in E. coli and Agrobacterium.
  • the T-DNA borders of a binary transformation vector can be derived from octopine-type or nopaline-type Ti plasmids or from both.
  • the T-DNA of a binary vector is only transferred to a eukaryotic cell in conjunction with a helper plasmid.
  • helper plasmid is meant a plasmid that is stably maintained in Agrobacterium and is at least carrying the set of vir genes necessary for enabling transfer of the T-DNA.
  • Said set of vir genes can be derived from either octopine-type or nopaline-type Ti plasmids or from both.
  • co-integrate transformation vector a T-DNA vector at least comprising: (a) a T-DNA region comprising at least one gene of interest and/or at least one
  • T-DNA borders and said set of vir genes of a said T-DNA vector can be derived from either octopine-type or nopaline-type Ti plasmids or from both.
  • Ra-derived plant transformation vector is meant a binary transformation vector in which the T-DNA borders are derived from a Ti plasmid and said binary transformation vector being used in conjunction with a helper Ri-plasmid carrying the necessary set of vir genes.
  • .5 for selection includes any gene which confers a phenotype to a cell in which it is expressed to facilitate the identification and/or selection of cells which are transfected or transformed with a gene construct of the invention or a derivative thereof.
  • Suitable selectable marker genes contemplated herein include the ampicillin resistance (Amp r , tetracycline resistance gene (Tc 1 ), bacterial kanamycin resistance gene (Kan r ), phosphinothricin resistance gene, neomycin i0 phosphotransferase gene (nptll), hygromycin resistance gene, ⁇ -glucuronidase (GUS) gene, chloramphenicol acetyltransferase (CAT) gene, green fluorescent protein (gfp) gene, and luciferase gene, amongst others.
  • agrolistics agrolistic transformation
  • agrolistic transfer a transformation method combining features of Agrobacterium-mediated transformation and of biolistic DNA delivery.
  • a T-DNA containing target plasmid is co-delivered with DNA/RNA enabling in plantal production of VirDl and VirD2 with or without, VirE2 (W09712046).
  • foreign DNA any DNA sequence that is introduced in the host's genome by recombinant techniques.
  • Said foreign DNA includes e.g. a T-DNA sequence or a part thereof such as the T-DNA sequence comprising the selectable marker in an expressible format.
  • Foreign DNA furthermore includes intervening DNA sequences as defined supra or infra.
  • the present invention provides a fusion protein comprising, essentially consisting or consisting of:
  • the DNA binding factor comprises, essentially consists of or consists of a DNA binding domain.
  • the present invention provides a fusion protein comprising, essentially consisting or consisting of:
  • the DNA binding factor according to the second aspect is also a DNA binding factor according to the first aspect, i.e. in preferred embodiments the DNA binding factor comprises, essentially consists of or consists of a DNA binding domain of a B-type ARR and is capable of specifically binding to a B-type ARR DNA motif, the DNA motif comprising the sequence 5'-(A/G)GAT(T/C)-3'.
  • the DNA binding domain of the B-type ARR is capable of specifically binding to the DNA motif comprising the sequence 5'-(A/G)GAT(T/C)-3'.
  • the DNA binding domain comprises, essentially consists or consists of the amino acid sequence XIX 2 X 3 WX 4 X 5 X S LX 7 XsPKXgXiOXi 1X12X13X14X15X16 Xi 7 Xi 8 Xi 9 X 2 oX 2 iRX 22 NVASHLQKX 23 R, wherein Xi is selected from R or K, preferably R; X 2 is selected from V, I, or M, preferably V; X 3 is selected from V, L, Q 5 T or W, preferably V; X 4 is selected from S or T; X 5 is any amino acid, preferably V, H, I, Q, F, D, P, E, or N; X 6 is selected from E, S, or P, preferably E; X 7 is selected from H or Q, preferably H; Xg is a stretch of 13 to 17 amino acids, i.e.
  • X 9 is selected from K 5 R 5 T or V 5 preferably K
  • X 10 is selected from I or L 5 preferably I
  • Xn is selected from L or V 5 preferably L
  • X 12 is selected from D 5 A 5 E 5 or K 5 preferably D or E
  • Xi 3 is selected from L 5 M 5 F, C 5 I 5 or Y, preferably L
  • X H is selected from M or L 5 preferably M
  • Xj 5 is selected from N 5 Q 5 or S 5 preferably N
  • Xi 6 is a stretch of 0 to 4 amino acids, , i.e.
  • E 5 L 5 M 5 N or R 5 preferably 0 amino acids
  • Xi 7 is selected from V or I 5 preferably V
  • Xj 8 is selected from selected from P 5 D 5 E 5 or Q 5 preferably P
  • X 19 is selected from G 5 K, W, or Y 5 preferably G
  • X 2 o is selected from L or I 5 preferably L
  • X 21 is selected from T or S 5 preferably T
  • X 22 is selected from E 5 N or S 5 preferably E
  • X 23 is selected from Y 5 F or H 5 preferably Y 5 and is capable of specifically binding to a B-type Arabidopsis response regulator.
  • Xi is R; and/or X 2 is V; and/or X 3 is V; and/or X 4 is S or T; and/or X 5 is V, H 5 1, Q 5 F, D 5 P 5 E, or N; and/or X 6 is E; and/or X 7 is H; X 8 is a stretch of 13 to 17 amino acids, i.e.
  • the DNA binding domain is selected from the group of (a) DNA binding domains of ARRl according to SEQ ID NO: 1, ARR2 according to SEQ ID NO: 2, ARRlO according to SEQ ID NO: 3, ARRI l according to SEQ ID NO: 4, ARRl 2 according to SEQ ID NO: 5, ARRl 3 according to SEQ ID NO: 6, ARRl 4 according to SEQ ID NO: 7, ARRl 8 according to SEQ ID NO: 8, ARRl 9 according to SEQ ID NO: 9, ARR20 according to SEQ ID NO: 10, ARR21 according to SEQ ID NO: 11, APRR2 according to SEQ ID NO: 60, APRR4 according to SEQ ID NO: 61, or CCAl according to SEQ ID NO: 62;
  • (c) a variant of a B-type ARR according to (a) or (b) comprising one or more modifications selected from the group consisting of amino acid exchanges, amino acid insertions, amino acid deletions, N-terminal truncations and C-terminal truncations capable of specifically binding to a B-type ARR DNA motif.
  • the DNA binding factor is: (a) selected from the group of polypeptides consisting of APRR2 according to SEQ ID NO: 63, APRR4 according to SEQ ID NO: 64, and CCAl according to SEQ ID NO: 65.
  • (c) a variant of a polypeptide according to (a) or (b) comprising one or more modifications selected from the group consisting of amino acid exchanges, amino acid insertions, amino acid deletions, N-terminal truncations and C-terminal truncations capable of specifically binding to a B-type ARR DNA motif.
  • the "plant other than Arabidopsis thaliana" to which any of the above embodiments refer is a monocotyledonous plant or a dicotyledonous plant. It is also contemplated within the present invention that such "other plants” can be lower plants, e.g. mosses such as Physcomitrella patens. It is also considered that B-type ARRs from other plants and especially B-type ARRs from non-plant organisms may have other DNA binding specificities than B-type ARRs from Arabidopsis thaliana.
  • the homolog of the DNA binding domain or the homolog of the B-type ARR protein is derived from Oryza sativa, Zea mays, Catharanthus roseus, Medicago truncatula, Poncirus trifoliata, Vitis vinifera, Brassica rapa, Vitis shuttleworthii, Allium cepa, Phaseolus vulgaris, Citrus Clementina, Solarium tuberosum, Sorghum bicolor, Pinus taeda or Populus deltoides.
  • the homolog of the B-type ARR protein is selected from response regulator proteins listed in table 2
  • the homolog of the DNA binding domain is selected from the DNA binding domains of the response regulator proteins listed in Table 2.
  • the transcriptional repressor domain is selected from the group consisting of an EAR motif, a paired amphipathic helix 3/histone deacetylase interaction domain (PAH3/HID), a histone
  • BZRl is a transcriptional repressor with dual roles in brassinosteroid homeostasis and
  • EAR motif repressor activity of the EAR motif can be determined with methods known to the person skilled in the art, e.g. by reporter gene assays using luciferase as reporter gene.
  • An EAR motif has "EAR motif repressor activity" within the meaning of the present invention, if the EAR motif exhibits a reduction of the expression of the reporter gene in a reporter gene assay by at
  • the EAR motif comprises the sequence LDLDLELRLGFA (SEQ ID NO: 52) or a variant thereof having EAR motif repressor activity.
  • the sequence according to SEQ ID NO: 52 is also known under the name SRDX motif (Hiratsuka et al. (2003) Plant J. 34(5), pp. 733-739).
  • the PAH3/HID is derived from a protein selected from the group consisting of Sin3A, SAP30L, and SAPl 8.
  • the DNA binding factor and the repressor domain are coupled directly to each other or via a linker.
  • the linker preferably comprises a polypeptide consisting of 1 to 100 amino acids, preferably 1 to 60 amino acids, more preferably 1 to 50 amino acids, more preferably 1 to 40 amino acids, and even more preferably said polypeptide consists of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, or 40 amino acids. It is especially preferred that the linker comprises one or more glycine residues.
  • the DNA binding factor is coupled to the N-terminal end of the linker and the transcriptional repressor domain is coupled to the C-terminal end of the linker.
  • the transcriptional repressor domain is coupled to the N- terminal end of the linker and the DNA binding factor is coupled to the C-terminal end of the linker are also considered within the present invention.
  • the fusion further comprises a nuclear localization signal.
  • the nuclear localisation signal is selected from the group consisting of PKKKRKV (SEQ ID NO: 53), KIPIK (SEQ ID NO: 54), SPPKAVKRPAATKKAGQAKKKKLDKEDES (SEQ ID NO: 55), MEEAVTMAPAAVSSAVVGDPMEYNAILRRKLEEDLE (SEQ ID NO: 56), KKRARL VRNRESAQLS RQRKK (SEQ ID NO: 57) and homologs and variants of any of these nuclear localisation signals.
  • the present invention further provides a polynucleotide comprising a nucleic acid sequence encoding the fusion protein of the invention as defined supra or infra or as set forth in preferred embodiments of the invention.
  • the present invention further provides a vector comprising said polynucleotide.
  • said vector is constructed in such a manner that the polynucleotide is operatively linked to expression control sequences allowing expression of the nucleic acid sequence encoding the fusion protein in prokaryotic and/or eukaryotic host cells.
  • the invention further provides a cell comprising said polynucleotide or said vector as defined supra or infra or as set forth in preferred embodiments of the invention.
  • the present invention further provides a transgenic plant comprising said polynucleotide, said vector or said cell as defined supra or infra or as set forth in preferred embodiments of the invention.
  • the present invention further provides parts, cells, or seeds of said transgenic plant.
  • the present invention also provides plants or propagating material thereof regenerated from a transgenic plant as defined supra or infra or as set forth in preferred embodiments.
  • the present invention is further directed at a process for making a transgenic plant, parts, cells, or seeds thereof or propagating material as defined supra or infra or as set forth in preferred embodiments comprising the step of transforming a cell or cells of a plant with a vector of the invention as set forth supra or infra.
  • the process comprises the further step of selecting transformed cells and regenerating of transformed plants from the cells.
  • the cell that can be used include any cell that is known in the art to be transfectable with a vector including without limitation tissue culture cells and developing floral tissues as in the floral-dip method (Clough SJ. and Bent AF (1998) Plant J. 16:735-43).
  • the present invention further relates to the use of a transgenic plant, parts, cells, or seeds thereof or propagating material as defined supra or infra or as set forth in preferred embodiments for producing seeds of enhanced size, with enhanced seed filling, with reduced seed loss and/or with more rapid germination, wherein the transgenic plants are cultured under culturing conditions and the preferably mature seeds are harvested.
  • the present invention also relates to the use of a transgenic plant, parts, cells, or seeds thereof or propagating material as defined supra or infra or as set forth in preferred embodiments for producing a live root system with increased root mass, root length and/or root branching, wherein the transgenic plant is cultured under culturing conditions.
  • this live root system with increased root mass, root length and/or root branching is useful for bioremediation and/or lodging resistance and/or altered mineral composition of the shoot and/or the harvested product and/or the root products.
  • this live root system is a rootstock used in a grafting procedure with a scion for improving the root-related characteristics of the resulting plant or tree (or similar).
  • the present invention further relates to a use of a transgenic plant of the invention for producing wood with modified characteristics, wherein the activity of the cambial tissue is modified, and wherein the transgenic plant is cultured under culturing conditions.
  • the present invention further relates to a use of a transgenic plant of the invention for producing a shoot with altered shoot architecture (i.e. with modified branching pattern), wherein the apical dominance in plants is altered, and wherein the transgenic plant is cultured under culturing conditions.
  • the present invention also relates to a use of a transgenic plant of the invention for producing leaves with altered leaf senescence, wherein the transgenic plant is cultured under culturing conditions.
  • the present invention also relates to a use of a transgenic plant of the invention for producing flowers with altered timing of reproduction, e.g. with earlier flower induction, wherein the transgenic plant is cultured under culturing conditions. It is contemplated within the present invention that the direction of any of the above-mentioned changes, such as altered leaf senescence, altered timing of reproduction, etc., may differ between different plant species. It is shown in Example 3.4 below that the 35S: ARRl SRDX transgenic Arabidopsis thaliana plants exhibit an earlier flowering. However, transgenic plants of other species expressing the fusion protein of the invention could exhibit a later flowering.
  • the present invention is further directed at the use of a transgenically expressed fusion protein of the invention as defined supra or infra or as set forth in preferred embodiments for enhancing the seed size, the seed filling, the root mass, the root length and/or the root branching and/or for reducing seed loss and/or germination time of a plant.
  • the present invention is also directed at the use of a transgenically expressed fusion protein of the invention as defined supra or infra or as set forth in preferred embodiments for modifying the characteristics of wood, for altering shoot architecture (i.e. modifying the branching pattern of the shoot), for altering leaf senescence and other senescence processes and/or for altering the timing of reproduction, e.g. causing earlier or later flower induction.
  • a transgenically expressed fusion protein of the invention as defined supra or infra or as set forth in preferred embodiments for modifying the characteristics of wood, for altering shoot architecture (i.e. modifying the branching pattern of the shoot), for altering leaf senescence and other senescence processes and/or for altering the timing of reproduction, e.g. causing earlier or later flower induction.
  • the fusion protein is tissue-specifically expressed.
  • the fusion protein is specifically expressed in tissue selected from the group consisting of root tissue, embryo tissue, endosperm tissue, and aleurone tissue.
  • the present invention further provides a method for enhancing the seed size, the seed filling, the root mass, the root length and/or the root branching and/or for reducing seed loss and/or germination time of a plant, comprising the steps of introducing by genetic engineering into the plant a nucleic acid; and - expressing said nucleic acid, wherein the nucleic acid is the polynucleotide or the vector of the invention as defined supra or infra or as set forth in preferred embodiments.
  • the expression of the polynucleotide is controlled by a tissue-specific regulatory element.
  • the tissue for which the regulatory element is specific is selected from the group consisting of root tissue, embryo tissue, endosperm tissue, and aleurone tissue.
  • the tissue-specific regulatory element is a promoter selected from the group consisting of the promoters disclosed in table 1.
  • the present invention provides a method for making seeds of enhanced size, with enhanced seed filling, reduced seed loss and/or more rapid germination, wherein the transgenic plant, parts, cells, seeds or propagating material thereof as defined supra or infra or as set forth in preferred embodiments are cultured under culruring conditions and preferably mature seeds being produced thereby are harvested.
  • the present invention further provides seeds obtainable by any of the methods described supra or infra.
  • the present invention also provides a method for making plants with increased root mass, root length and/or root branching and/or for reducing seed loss and/or germination time of a plant, wherein the transgenic plant, parts, cells, seeds or propagating material thereof as defined supra or infra or as set forth in preferred embodiments are cultured under culturing conditions.
  • the fusion proteins or the transgenic plants as defined supra or infra or as set forth in preferred embodiments can be used to enhance the resistance to pathogens which induce cell division in plants.
  • pathogens include inter alia Agrobacterium, certain nematodes, and Plasmodiophora brassicae in the case of Brassica species (see e.g. Siemens et al., MoI. Plant Mic. Interact. 19, 480-494, 2006).
  • the present invention also provide a method for enhancing the resistance to pathogens which induce cell division in plants, the methods comprising the steps of introducing by genetic engineering into the plant a nucleic acid; and expressing said nucleic acid; wherein the nucleic acid is the polynucleotide or the vector of the invention as defined supra or infra or as set forth in preferred embodiments. It is especially preferred that the polynucleotide is controlled by a pathogen-specific regulatory element, preferably by a pathogen-inducible promoter as shown in Table 1.
  • variants of the DNA binding factor and/or the repressor domain of the invention may comprise one or more further modifications selected from the group consisting of amino acid exchanges, amino acid insertions, and amino acid deletions.
  • the deletions can be internal deletions, N-terminal truncations and/or C-terminal truncations.
  • a protein variant differing from the protein from which it is derived by deletions only may be termed a protein "fragment".
  • the DNA binding factor variant and/or the repressor domain variant preferably comprise independently from each other from 1 to 100, from 1 to 80, from 1 to 60, from 1 to 50, from 1 to 40, from 1 to 30, from 1 to 20, from 1 to 15, from 1 to 12, or from 1 to 10 modifications.
  • modifications can be any combination of amino acid exchanges, amino acid insertions, and amino acid deletions (i.e. internal deletions, N- terminal truncations and C-terminal truncations).
  • the term "modification" in this context is to be understood as any change to an amino acid as compared to the corresponding protein sequence.
  • the DNA binding factor variant and/or the repressor domain variant comprise independently from each other from 1 to 50, from 1 to 40, from 1 to 30, from 1 to 20, from 1 to 15, from 1 to 12, or from 1 to 10 amino acid insertions.
  • the DNA binding factor variant and/or the repressor domain variant comprise independently from each other from 1 to 50, from 1 to 40, from 1 to 30, from 1 to 20, from 1 to 15, from 1 to 12, or from 1 to 10 amino acid deletions. In other preferred embodiments thereof the DNA binding factor variant and/or the repressor domain variant comprise independently from each other from 1 to 50, from 1 to 40, from 1 to 30, from 1 to 20, from 1 to 15, from 1 to 12, or from 1 to 10 amino acid substitutions.
  • the further modification leads to a molecule that is at least 50% identical to the DNA binding factor or the repressor domain, respectively, from which it is derived, preferably at least 60%, at least 70%, at least 80%, at least 85%, at least 90% or at least 95% identical to the DNA binding factor or the repressor domain, respectively.
  • the invention allows obtaining favorable phenotype features, but avoiding unfavorable phenotype features. For example, enhanced root branching may be obtained without dwarf growth of other plant parts. The same applies in an analogous manner to the seed size, the seed filling or the germination time. As a result, yield parameters, like the harvest index are considerably improved.
  • the target tissue is preferably selected from the group consisting of "root tissue, embryo tissue, endosperm tissue, and aleurone tissue". If the target tissue is root tissue and other tissue is not target tissue, a plant is obtained, which shows enhanced root branching but unaltered shoot growth. If the target tissue is embryo tissue, endosperm tissue or aleurone tissue, but other tissue is not target tissue, larger seeds are obtained at unaltered other properties of the plant. It is, however, also possible to combine both said subgroups of target tissue, provided that other tissue is not target tissue. This will result in a plant, wherein both, root branching and seed size are enhanced. This is most favorable since the increase in yield parameters is enhanced further.
  • Tissue specific expression of fusion proteins may be achieved in that the expression of the compound is controlled by a regulatory element, which is tissue specific, i.e. promotes expression only in the target tissue and not in tissue not being target tissue.
  • the transgenic plant of the invention is naturally not capable of reducing cytokinin signaling activity tissue-specifically.
  • a foreign DNA sequence is introduced by genetic engineering, which encodes for at least one nucleic acid or at least one protein or peptide, wherein the foreign DNA sequence stands under the control of a tissue-specific regulatory element.
  • the transgenic plant of the invention produces seeds of enhanced size, enhanced seed filling, reduced seed loss, reduced germination time and/or produces roots with enhanced branching, length and/or mass.
  • the invention further comprises a method for enhancing the seed size, the seed filling, the root mass, the root length and/or the root branching and/or for reducing seed loss and/or germination time of a plant, wherein the cytokinin signaling activity is essentially unaltered in tissue not being target tissue.
  • the target tissue is preferably selected from the group consisting of "root tissue, embryo tissue, endosperm tissue, and aleurone tissue".
  • the tissue-specific regulatory element may be a promoter selected from the group consisting of the elements of the table 1 or any other promoter of the said specificity. Further details about applicable promoters and how to identify such promoters are obtainable from the following data sources.
  • Plants with an enhanced root system are better adapted to stress, they enhance plant vigour, they grow better on soil poor in nutritional elements (minerals), they show improved growth with limited water resources and enhanced resistance to drought finally leading to improved yield parameters, in particular an improved harvest index. They can also be used for phytoremediation, i.e. plant mediated removal of toxic substances from soil, and/or prevention and/or arrest of soil erosion.
  • the methods of the invention as well as the plants thereof typically result in enhanced growth of the primary root and/or strongly enhanced root branching. Improvement of the root system in particular is favourable for staple crops, like sugar beet, manioc, yams, sweet potato, vegetables with consumable root parts like carrots and radish, and medicinal plants with usable root parts, like ginseng. But also the yield parameters of other crops like wheat, maize etc. are increased, since the plant growth is improved due to the comparatively better uptake of water and nutritional substances from the soil.
  • Plants with an increased seed size provide higher yield parameters for obvious reasons.
  • the inventors believe that the above depicted advantageous properties of the transgenic plants of the invention are mainly achieved by means of a reduction in cytokinin signaling.
  • the fusion proteins of the present invention act as transcriptional repressors in other pathways than the cytokinin signaling pathway, e.g. they may also interfere with ethylene signaling and/or red-light signaling pathways.
  • the present invention is applicable to any plant, in particular to monocotyledonous plants and dicotyledonous plants including a fodder or forage legume, ornamental plant, food crop, tree, or shrub selected from the list comprising Acacia spp., Acer spp., Actinidia spp., Aesculus spp., Agathis australis, Albizia amara, Alsophila tricolor, Andropogon spp., Arachis spp, Areca catechu, Astelia fragrans, Astragalus cicer, Avena sativa, Baikiaea plurijuga, Betula spp., Brassica spp., Bruguiera gymnorrhiza, Burkea africana, Butea frondosa, Cadaba farinosa, Calliandra spp, Camellia sinensis, Canna indica, Capsicum spp., Cassia spp., Centroema pubescens, Chaen
  • Means for introducing foreign resp. recombinant DNA into plant tissue or cells include, but are not limited to, transformation using CaCl 2 and variations thereof, in particular the method described by Hanahan (Hanahan, D. (1983) J. MoI. Biol. 166, 557-580), direct DNA uptake into protoplasts (Krens, F.A. et al (1982) Nature 296, 72-74); Paszkowski J. et al. (1984) EMBO J. 3, 2717-2722), PEG-mediated uptake to protoplasts (Armstrong CL. et al.
  • Methods for transformation of monocotyledonous plants are well known in the art and include Agrobacterium-mediated transformation (WO 97/48814; WO 98/54961; WO 94/00977; WO 98/17813; WO 99/04618; WO 95/06722), microprojectile bombardment (US 5,969,213; US 5,736,369; WO 94/13822; US 5,874,265 / US 5,990,390; US 5,405,765; US 5,955,362), DNA uptake (WO 93/18168), microinjection of Agrobacterium cells (DE 43 092 03) and sonication (US 5,693,512).
  • Agrobacterium-mediated transformation WO 97/48814; WO 98/54961; WO 94/00977; WO 98/17813; WO 99/04618; WO 95/06722
  • microprojectile bombardment US 5,969,213; US 5,736,369; WO 94/
  • a microparticle is propelled into a cell to produce a transformed cell.
  • Any suitable ballistic cell transformation methodology and apparatus can be used in performing the present invention. Exemplary apparatus and procedures are disclosed in US 5,122,466 and US 4,945,050.
  • the gene construct may incorporate a plasmid capable of 5 replicating in the cell to be transformed. Examples of microparticles suitable for use in such systems include 1 to 5 ⁇ m gold spheres.
  • the DNA construct may be deposited on the microparticle by any suitable technique, such as by precipitation. A whole plant may be regenerated from the transformed or transformed cell, in accordance with procedures well known in the art. Plant tissue capable of subsequent clonal propagation, whether by
  • tissue targets include leaf disks, pollen, embryos, cotyledons, hypocotyls, megagametophytes, callus tissue, existing meristematic tissue (e.g.,
  • apical meristem 15 apical meristem, axillary buds, and root meristems), and induced meristem tissue (e.g., cotyledon meristem and hypocotyl meristem).
  • induced meristem tissue e.g., cotyledon meristem and hypocotyl meristem.
  • the plant produced according to the inventive method is transfected or transformed with a genetic sequence, or amenable to the introduction of a fusion protein by any art-recognized means, such as microprojectile bombardment, microinjection,
  • Agrobacterium-mediated transformation including in planta transformation), protoplast fusion, or electroporation, amongst others. Most preferably said plant is produced by Agrobacterium-mediated transformation.
  • Agrobacterium-mediated transformation or agrolistic transformation of plants, yeast, moulds or filamentous fungi is based on the transfer of part of the transformation vector sequences, called the T-DNA, to the nucleus and on
  • Fig. 1 Sequence comparison and phylogenetic analysis of DNA binding domains of B-type SO ARRs
  • RNA samples were isolated from 35 days old plants and the transcript was analysed by 0 Northern blot hybridization using a probe specific for the ARRl-SRDX gene fusion. The actin transcript was used as loading control.
  • WT, wild type Col-0; ARR1 S 8 and ARR1_S_1O are different, independent lines of 35S::ARR1-SRDX transgenic plants.
  • Fig. 3 Plant phenotype of 35S: : ARRl-SRDX transgenic plants.
  • Root phenotype of 35S : ARRl-SRDX transgenic plants.
  • Results shown in (b-c) for each line represent means from at least three independent0 replicates. Error bars represent SD (n>15).
  • 35S ARRl -SRDX plants are less sensitive to cytokinin in a chlorophyll retention assay.
  • Fig. 7 Cytokinin sensitivity in roots of 35S: : ARRl-SRDX transgenic plants.
  • 35S .ARRl-SRDX gene expression dampens the primary cytokinin response.
  • Total RNA was isolated from 5-days-old wild type and 35S: .ARRl-SRDX seedlings treated with 5 ⁇ M BA for Omin, 15min, 30min and 120min.
  • Northern blots were hybridized with a probe specific for the cytokinin response gene ARR5. Hybridisation with an actin probe was used as loading control.
  • the activation of the ARR6. GUS reporter gene was measured without and 16 h after the addition of 500 nM trans-zea ⁇ n (tZ).
  • the ARR6. GUS reporter construct and a 35S. GUS construct without any effector plasmid were used as controls.
  • Protoplasts were co-transfected with the ARR6. GUS reporter and an effector plasmid expressing ARRl, ARRl-SRDX or both effector plasmids simultaneously.
  • the fusion of the SRDX domain to ARRl effectively repressed the transactivation capacity of ARRl .
  • Variations in transformation efficiencies were normalized by using a 35S:NAN reporter gene construct.
  • the mean values and SD of four independent transfection assays were calculated and shown as relative GUS/NAN activity units.
  • FIG. 10 Schematic Representation of the ARRl-SRDX Fusion Protein.
  • This figure shows a scheme of the ARRl-SRDX fusion protein with the junction between ARRl and the SRDX peptide highlighted in the excerpt. The size of the domains is not drawn to scale.
  • RR response regulator domain
  • MYB DNA-binding domain
  • SRDX SRDX domain.
  • the indicated amino acid sequence and nucleotide sequence are listed in the sequence listing as SEQ ID NO: 66 and SEQ ID NO: 67, respectively.
  • the CRES-T is based on the dominant repression of target gene expression.
  • the DNA-binding domains and thus the promoter target sequences of those transcription factors should be similar. Therefore we analyzed first the similarity of the DNA-binding domains of B-type ARRs and of pseudo response regulators APRR2 and APRR4, which contain a MYB DNA-binding domain (Makino et al, 2000).
  • the respective domains were identified using the Pfam programme (Finn et al, 2006) and subsequently the sequences were aligned using the Clustal W algorithm (Thompson et al, 1994)(SEQ ID NO: 1 to SEQ ID NO: 11, SEQ ID NO: 60 to SEQ ID NO: 61; Fig. Ia).
  • ARRl The DNA binding domain of ARRl (SEQ ID NO: 1) shares the highest homology with ARR2 (SEQ ID NO: 2) and the lowest with ARRl 9 (SEQ ID NO: 9) (96% and 47% identity, respectively).
  • the high degree of conservation of amino acids important for DNA recognition (Fig. Ia) and the fact that several B-type ARRs have been shown to bind to the same or very similar sequence motifs (Sakai et al. 2000; Hosoda et al. 2002), are consistent with a redundant function of B-type ARRs.
  • ARRl 9 (SEQ ID NO: 9) and ARR20 (SEQ ID NO: 10) as well as ARR21 (SEQ ID NO: 11) and ARR13 (SEQ ID NO: 6) form separate groups (Fig. Ib).
  • ARRl 3 was included in this alignment although Pfam did not detect a MYB domain in this protein using the default cut off of 1.
  • the protein coding region of the ARRl gene was amplified by PCR using a cDNA library from Arabidopsis thaliana C24 (Minet et al., 1992).
  • the DNA fragment coding for the SRDX peptide (SEQ ID NO: 52: LDLDLELRLGFA; (Hiratsu et al., 2003)) was synthesized with a TAA stop codon and a Bsr GI restriction site at the 3' end and an in frame Hha I site at the 5' end.
  • the ARRl gene was isolated from the plasmid pDONR201 (Invitrogen, Carlsbad, USA) by restriction digestion with Bsr GI and the resulting fragment was further digested with Hha I.
  • the appropriate DNA fragments were ligated and recloned into entry vector pDONR201 (Invitrogen, Carlsbad, USA).
  • the resulting ARRl-SRDX gene was shuttled into the vector pB2GW7 (Invitrogen, Carlsbad, USA) for overexpression under the control of the 35S promoter.
  • the construct obtained in 2.1 was transformed using Agrobacterium tumefaciens mediated transformation into wild-type Arabidopsis plants (CoI-O) by the floral dip method (Clough and Bent, 1998).
  • ARR1_S_8 contained a single T-DNA insertion locus and ARR1_S_1O carried insertions at two independent loci.
  • the SRDX-specific probe was prepared by amplifying the SRDX containing segment of the ARRl-SRDX gene using the following primers 5 1 - ATGAGCGC ACTCGATC-3 1 (SEQ ID NO: 58) and 5'- AGTTTGTACAAGAAAGO 1 (SEQ ID NO: 59).
  • Example 3 Phenotypical Characterization of the Transgenic Plants expressing the ARRl-SRDX Fusion Protein Example 3.1 Plant material and growth conditions
  • Plants of the Columbia (CoI-O) accession of Arabidopsis thaliana was used as wild type. The plants were grown in the greenhouse on soil at 22 0 C under long-day conditions (16 h light/8 h dark). For in vitro experiments, seeds were surface-sterilized with saturated calcium hypo-chlorate solution. After sowing they were kept at 4 0 C for 3 d in the dark and then exposed to white light ( ⁇ 75 ⁇ E). Seedlings were grown at 22 °C on media containing Ix Murashige and Skoog (MS) salts, 3% sucrose, 0.05% MES and 0.9% agarose (Merck) unless specified otherwise. For flowering phenotype total number of rosette leaves was counted upon flower bud initiation.
  • MS Ix Murashige and Skoog
  • the transgenic plants expressing the ARRl-SRDX construct displayed a strong pleiotropic shoot phenotype. Plants were generally smaller in habitus and showed enhanced branching of the shoot. This effect was stronger in line ARR1 S 8 than in ARR1_S_1O (Fig. 3 a).
  • the leaves of the dominant repressors were strongly reduced in both size and number when compared to the wild-type plants. In the strongest expressing line ARR1 S 8 even the true leaves were only about the size of the cotyledons in the wild type (Fig. 3b). In addition, the formation of new leaves was slow in the transgenic lines. While the wild-type plant had on average nine rosette leaves 20 DAG (days after germination), the ARR 1 -SRDX expressing plants had only seven leaves at that time point (Fig 3c).
  • Arabidopsis seeds were grown on vertical plates containing different concentration of BA ranging from 0.01 ⁇ M to 1.0 raM. 0.1% dimethyl sulfoxide (DMSO) was included as vehicle control. The primary root lengths were marked on day four and nine after germination. Photographs were taken with a digital camera (Nikon Coolpix 8800) and root lengths were determined using Scion Image program version beta 4.02 (www.scioncorp.com). The number of lateral roots emerging from the epidermis of the primary root was counted under a microscope ten DAG. The experiments were performed using three independent replicates and 15 seedlings in each replicate.
  • DMSO dimethyl sulfoxide
  • ARRl-SRDX transgenic plants showed a generally enhanced root system when compared to the wild type (Fig. 4a). While the ARR_S_8 plants had only a slightly longer primary root than the wild type, the primary root of line ARR_S_10 was more than 30% longer (34.9 ⁇ 3.1 mm in wild type compared to 51.9 ⁇ 6.6 mm in line ARR_S_10; Fig. 4b). The difference between the transgenic lines and the wild type was more pronounced in the number of lateral roots.
  • the 35S.ARR1 _SRDX transgenic plants flowered earlier than wild type (Fig. 5a). To quantify this phenotype, the number of days from germination to the opening of the first flower bud was counted. In the wild type the first flower buds opened 19 days after germination. In contrast, both lines 8 and 10 flowered already around 14 days after germination (Fig. 5b) In the 35S .ARRl-SRDX transgenic plants, all reproductive organs were reduced in size. Both, the flowers and the siliques were smaller compared to wild type. This was more pronounced in line ARR1_S_8, where the flowers were only half the size of the wild type (Fig. 5c).
  • the phenotype of the 35S: ARRl-SRDX plants is reminiscent of plants with a reduced cytokinin signaling (Higuchi et al., 2004; Nishimura et al., 2004; Riefler et al., 2006).
  • Cytokinin is known to delay the onset of leaf senescence and to increase the chlorophyll retention in detached leaves incubated in the dark (Richmond and Lang, 1957; Riefler et al., 2006).
  • the chlorophyll retention assay was performed as described by (Riefler et al., 2006).
  • DMSO DMSO in small Petri dishes for 10 d at RT in the dark. Three replicates of each genotype, each consisting of five leaves were taken for measurement. Chlorophyll was extracted with methanol for 24 h in the dark. The amount of chlorophyll was measured with a spectrophotometer, normalized to fresh weight, and the chlorophyll content was calculated as
  • the transcript level of ARR5 which encodes a member of the A-type ARRs, is rapidly induced by cytokinin (D'Agostino et al, 2000) and it has often been used as a molecular maker for the cytokinin response in Arabidopsis (D'Agostino et al, 2000; Romanov et al, 2002). It was also shown that the A-type ARRs are target genes of the B-type ARRs (Hwang and Sheen, 2001). Fig. 8 shows that the transcript level of ARR5 was rapidly
  • the phenotype of the 35S: ARRl-SRDX transgenic plants resembled in various aspects the phenotype of cytokinin receptor triple mutants (Higuchi et al., 2004; Nishimura et al., 2004; Riefler et al., 2006). As in those mutants the shoot growth in 35S.ARR1-SRDX plants was strongly retarded, with a reduced plastochrone and the formation of a reduced number of
  • Cytokinins are known to play a crucial role in plant senescence, which is in part mimicked by the dark-induced chlorophyll retention assay we used in our analysis (Riefler et al. 5 2006). Previous analysis using different cytokinin receptor mutant combinations determined AHK3 to play crucial roles mediating the cytokinin function in this process. 35S: ARRl -SRDX plants show a complete resistance to cytokinin in the chlorophyll retention assay, which is similar to the phenotype of ahk2 ahk3 receptor mutants (Riefler et al., 2006).
  • ARR2 mutant plants flower earlier than wild type (Hass et al., 2004), while triple mutants and cytokinin-deficient plants show retarded flowering. It could be that the negative regulatory function of ARR2 in controlling flowering is lost by its repression.
  • the shoot morphology as well as the complete resistance to cytokinin of leaves in the chlorophyll retention assay indicates a very strong suppressor activity of the ARRl-SRDX protein.
  • a shoot phenotype was not reported even for various triple B-type arr mutants (Mason et al., 2005).
  • the primary roots are longer and more lateral roots are formed (Higuchi et al., 2004; Mason et al., 2005; Nishimura et al., 2004; Riefler et al., 2006; Werner et al., 2003).
  • the reduced cytokinin sensitivity of roots of 35S.ARR1-SRDX transgenic lines is similar to changes seen in various mutants with a reduced cytokinin status (Werner et al, 2003).
  • the inducibility of the cytokinin response gene ARR5 was clearly dampened in both dominant repressor lines, indicating that the ARRl-SRDX protein interferes directly with the activity of transcription factors mediating the cytokinin response.
  • the reduction of gene induction is comparable to the arrl, 10, 12 triple mutant (Mason et al, 2005), but clearly weaker than that of the receptor triple mutants (Higuchi et al, 2004). This may indicate that transcription of the A-type ARRs might be also regulated via an AHK dependent, but B-type
  • AHK dependent manner by cytokinin The six members of this class of transcription factors rapidly localize to the nucleus upon cytokinin treatment and have been shown to redundantly regulate several aspects of plant development. The function of this family of transcription factors is only partially overlapping with those of the B-type ARRs. However, ARR5 was shown to be one of the genes transcriptionally regulated by both gene families. This might explain, why in the 35S: ARRl -SRDX plans the induction of ARR5 is only dampened and not completely abolished ( Figure 8 + (Rashotte et al, 2006).
  • the reporter plasmid was generated by amplifying the 1000 bp fragment directly upstream of the ARR6 gene using the forward primer 5'- GCAAGCTTACAATCACAACAGCTCATGAACAAAATC-3' (SEQ ID NO: 68) and the reverse primer 5 '-GCTCTAGAGAAACCATGGTGGCAGTGGTTGGGC-B ' (SEQ ID NO: 69).
  • the resulting PCR product was digested with HindUl and Xbal and ligated into the pBT10-GUS vector (Sprenger-Haussels and Weisshaar, 2000).
  • the 35S.ARR1 gene was generated by shuttling the ARRl gene from the pDONR201-ARRl vector (Dortay et al., 2006) into the pB2GW7 vector (Karimi et al., 2002) for expression under the control of the 35S promoter.
  • a dominant repressor for the B-type ARRs was generated by introducing a 36 bp long DNA sequence encoding the SRDX domain (LDLDLELRLGFA (SEQ ID NO: 52); Hiratsu et al., 2003) 20 nucleotides 5' of the ARRl stop codon (Figure 10).
  • Protoplast isolation and transformation was carried out according to the method described by Hwang and Sheen (Hwang and Sheen, 2001). For isolation of mesophyll protoplasts 4-5 weeks old rosette leaves were used. Transformation of protoplasts was mediated by 40% PEG solution. For cytokinin treatment protoplasts were incubated overnight with 500 nM trans-zea ⁇ n (tZ). For the transactivation assays, 9 ⁇ g of the ARR6. GUS reporter plasmid and 14 ⁇ g of each effector plasmid carrying 35S.ARR1 and 35S.ARR1-SRDX were used. For normalization 3 ⁇ g of a plasmid harboring the 35S.NAN gene (Kirby and Kavanagh,
  • the present invention provides transgenic plants and methods for their production which are superior over the single, double and triple mutants known from the prior 5 art.
  • the transgenic plants of the present invention exhibit advantageous properties such as enhanced seed size, enhanced seed filling, reduced seed loss, enhanced root mass, enhanced root length, enhanced root branching, reduced germination time, altered leaf senescence and/or altered timing of reproduction.
  • Floral dip a simplified method forAgrobacterium- mediated transformation of Arabidopsis thaliana. Plant J., 16, 735-743.
  • NAN fusions a synthetic sialidase reporter gene as a 30 sensitive and versatile partner for GUS. Plant J. 32, 391 -400.
  • the response regulator ARR2 A pollen-specific transcription factor involved in the expression of nuclear genes for components of mitochondrial complex I in Arabidopsis. MoI. Genet. Genomics, 265, 2-13.

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Abstract

L'invention porte sur des protéines de fusion capables d'agir en tant que répresseurs transcriptionnels de la signalisation par les cytokinines, sur des polynucléotides codants pour ces protéines de fusion, sur des vecteurs et des cellules comportant ces polynucléotides et sur des plantes transgéniques et parties de celles-ci comportant ces polynucléotides, vecteurs et cellules. L'invention porte en outre sur un procédé de fabrication de ces plantes transgéniques et sur l'utilisation de ces plantes transgéniques pour produire des graines de taille augmentée avec un contenu des graines augmenté, avec une perte réduite de graines et/ou avec une germination plus rapide, et/ou pour produire un système de racines vives avec une masse des racines, une longueur des racines et/ou une ramification des racines augmentées. L'invention porte également sur un procédé pour augmenter la taille des graines, pour améliorer le contenu des graines, pour réduire la perte de graines et/ou pour réduire le temps de germination et/ou le temps de reproduction, et/ou pour améliorer la masse des racines, la longueur des racines et/ou la ramification des racines d'une plante, ainsi que sur les graines pouvant être obtenues par les procédés de la présente invention.
PCT/EP2007/008331 2006-09-25 2007-09-25 Répresseurs transcriptionnels de la signalisation par cytokinine et leur utilisation WO2008037431A1 (fr)

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WO2014054602A1 (fr) * 2012-10-02 2014-04-10 住友ゴム工業株式会社 Procédé de régulation de l'expression d'une protéine spécifique au moyen d'un facteur de transcription répondant à la cytokinine, plante produisant des isoprénoïdes, comportant un gène codant pour un facteur de transcription répondant à la cytokinine introduit en son sein, et procédé de production de polyisoprénoïdes au moyen de ladite plante produisant des isoprénoïdes
JP2014073082A (ja) * 2012-10-02 2014-04-24 Sumitomo Rubber Ind Ltd 特定の蛋白質の発現をサイトカイニン応答転写因子により調整する方法、サイトカイニン応答転写因子をコードする遺伝子が導入されたイソプレノイド産生植物、及び該イソプレノイド産生植物を用いたポリイソプレノイドの製造方法
US10000763B2 (en) 2012-10-02 2018-06-19 Sumitomo Rubber Industries, Ltd. Method for regulating expression of specific protein using cytokinin-responsive transcription factor, isoprenoid-producing plant having gene encoding cytokinin-responsive transcription factor introduced therein, and method for producing polyisoprenoid using said isoprenoid-producing plant
CN110079537A (zh) * 2019-05-27 2019-08-02 河南科技大学 葡萄细胞分裂素响应调节因子VvRR基因及其编码蛋白和应用

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US9187761B2 (en) 2015-11-17
AU2007302306A1 (en) 2008-04-03
ATE516358T1 (de) 2011-07-15
EP2121935B1 (fr) 2011-07-13
EP2121935A1 (fr) 2009-11-25
US20100115666A1 (en) 2010-05-06
PL2121935T3 (pl) 2011-12-30
CA2667396C (fr) 2017-03-28

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